There’s difference of opinion on the primary cause–long-term climate cycles or man-made global warming, but there’s no question that our climate has changed, and quickly enough that it should be noticeable to anyone with even a few grey hairs. That’s because there’s been significant, measured change in our climate just since 1990, a mere 26 years. The average dates of first and last frost have changed by 4 to 5 days, with an earlier last frost in the spring, and a later first frost in the fall. However, the change hasn’t been equal across the U.S., which should surprise nobody. In the Eastern U.S. the increased length of our growing season has increased by less than half as much–2 days at most. However, first and last frost dates don’t describe in-season temperature changes, and as you might expect these have also increased.
What does this mean for farmers? If you’re still planting the same crop maturities, particularly corn and soybeans, that you were 20 years ago it might be time to re-evaluate. Cornell University has found that the ideal maturity rating of soybean varieties for a particular area of the state is later than when in a previous evaluation. Therefore, if, for instance, you’ve been planting Group 1.2 maturity soybeans for many years you should give some consideration to a slightly later variety–perhaps Group 1.5 maturity. Or if you’ve been planting 95 RM corn hybrids, considering a move to 98 RM hybrids for at least a portion of your acreage, This assumes, of course that you’ve been able to mature the crops without difficulty, year in and year out–which especially in the case of corn harvested for silage, is NOT always the case. Because it’s still better to plant hybrids that will reliably mature on your farm, under your management, than to shoot for the moon and wind up with an immature crop.